Dark Matter in the CP-violating NMSSM

TL;DR

This paper investigates how CP-violation in the NMSSM, caused by a complex parameter , affects the properties and relic abundance of light neutralino dark matter, considering experimental constraints.

Contribution

It provides the first analysis of the impact of  phase on neutralino dark matter relic abundance in the CP-violating NMSSM.

Findings

The  phase significantly influences the neutralino relic density.

Light neutralinos (~10 GeV) can be viable dark matter candidates.

CP-violation modifies Higgs and neutralino phenomenology in the model.

Abstract

In the Next-to-Minimal Supersymmetric Standard Model there is a strong correlation between the mass terms corresponding to the singlet Higgs and the singlino interaction states, both of which are proportional to the parameter $\kappa$. If this parameter is complex, explicit CP-violation occurs in the Higgs as well as the neutralino sectors of the model at the tree level, unlike in the minimal scenario. A small magnitude of $\kappa$ typically yields a $\cal{O}$(10) GeV lightest neutralino with a dominant singlino component. In such a scenario, the phase of $\kappa$, beside modifying the properties of the five Higgs bosons, can also have a crucial impact on the phenomenology of the neutralino dark matter. In this study we perform a first investigation of this impact on the relic abundance of the dark matter solutions with sub-100 GeV masses, obtained for parameter space configurations of the model that are consistent with a variety of current experimental data.